How to get silhouette with contour rendering in Cycles
Render your scene twice. First in cycles and then in Blender Internal. Leave cycles materials in BI and change the alpha to transparent in the shading setting. There will be edges only in BI. When you get both of your scenes rendered. Use the compositor with the "alpha over" node.

If you want your human to be a shadeless white, you could use a material index node in Cycles that creates a mask of your object without shadows but it will still cast shadows under image. 

Node setup:



Test render: